A concise synthetic route to the conduritols from pentoses
作者:Lise Keinicke、Robert Madsen
DOI:10.1039/b512009h
日期:——
A short synthetic strategy for preparation of the conduritols is described. The key step employs a zinc-mediated fragmentation of protected methyl 5-deoxy-5-iodo-d-pentofuranosides followed by an allylation of the intermediate aldehyde in the same pot. The allylation is performed with 3-bromopropenyl benzoate and occurs with good diastereoselectivity. An amino group can be introduced in the product
Role of a Protected Vicinal Diol Controller in Intramolecular [3 + 2] Cycloaddition Reactions of Chiral Acyclic Alkenyl Nitrones: Syntheses of Enantiomerically Pure Tetrasubstituted Cyclobutylamines
作者:Seiki Saito、Teruhiko Ishikawa、Toshio Moriwake
DOI:10.1021/jo00095a008
日期:1994.8
Intramolecular cycloaddition reactions of C-5-chain acyclic alkenyl nitrones such as N-[(2S,3S)-2,3-bis-(tert-butyldimethylsiloxy)-4-pentenylidene]benzylamine N-oxide and its C(5)-substituted derivatives lead to fused isoxazolidines (bicyclo[3.2.0] framework) with very high diastereomeric excess. These isoxazolidines can readily be converted to optically active tetrasubstituted cyclobutylamines.